1. Field of the Invention
The present invention relates generally to catheters and, in particular, to catheters that can be curved or bent at their distal ends or other selected locations, and methods for making and deploying such catheters.
2. Description of the Related Art
Catheters frequently have “preset” curves in them to enhance the physician's ability to introduce the catheter to the desired location. Usually, this curve is “set” in the catheter by first bending the catheter to the desired shape, then applying heat to the catheter while in this curved state, and then allowing the catheter to cool while still in this curved shape. The plastic memory of the polymer allows the curved shape to be maintained after cooling. In some cases, the catheter can be curved without heat by cold working the catheter into a curved shape.
The existing methods of curving catheters suffer from a number of disadvantages. First, the curved shape requires some rigidity of the catheter to maintain the curvature. Second, the curve can only be “set” outside of the body. Third, the soft wall of the catheter needed to make the curve shape often becomes crushed or kinked during use. Fourth, a small size and tight curvature of the catheter is difficult to achieve.
Thus, there is a need in the industry for an improved method and apparatus for making and deploying catheters that allow the catheter to be curved or bent at its distal end or other selected locations during deployment.